Definition of Term

lapillus

(english)
The otolilth in the utriculus. It is held in a vertical position against the cells of the utricular macula which is innervated by the anterior branch of cranial nerve VIII (the stato-acoustic nerve). Movements of the lapillus send signals to the brain and help the fish to maintain equilibrium. It is usually very small but is the largest otolith in Siluridae. Also called utriculith. (See also: otolith, utriculus)